Pumping device for promoting patients breathing

ABSTRACT

A pumping device having a bellow-type pumping assembly having a stationary and an oscillating end portion, and a mechanism for reciprocating said end portion between a given minimum volume and an adjustable maximum volume position, the said mechanism including a spring biased connecting rod, designed to transmit a force not greater than a given value, and a motor reciprocated arm along which one end of said rod is pivotally connected at operator adjustable positions for modifying the actual length of said arm and therefore the amplitude of the variation of said volume, while the pressure built-up in said chamber cannot be higher than that provided by the force which can be applied to said oscillating end portion by said spring biased rod.

United States Patent [191 Fumagalli PUMPING DEVICE FOR PROMOTIN PATIENTS BREATHING [76] Inventor: Giovanni Fumagalli, 11, Via delle Primule, 20146 Milano, Italy [22] Filed: June 9, 1972 [21] Appl. No.: 261,160

[30] Foreign Application Priority Data.

June 15, 1971 Italy 25864/71 [52] US. Cl 92/13.2, 74/48, 92/135, 92/137, 128/145.6, 128/203, 287/58 CT, 417/472 [51] Int. Cl. F01b 19/00, FOlb 31/14 [58] Field of Search 92/132, 13.5, 13.7, 13.8,

[56] References Cited UNITED STATES PATENTS 905,823 12/1908 Montgomery 92/137 X 1,609,292 12/1926 Burch 74/48 2,167,266 7/1939 Kimball 251/61 X 2,197,018 4/1940 Demmler 74/48 2,228,983 l/l94l Bloomheart.... 128/203 X 2,587,395 2/1952 Sheen 92/137 X 2,792,156 5/1957 Camp 92/13.7X

[ June 25,1974

2,873,611 2/1959 Biermann 92/60.5 X 3,161,264 12/1964 Isaacson 287/58 CT X 3,257,952 6/1966 McConnick 92/605 X 3,443,521 5/1969 Stender 92/137 X 3,529,908 9/1970 Smith 92/132 X 3,651,804 3/1972 Spiller 128/1456 Primary Examiner-Edgar W. Geoghegan Assistant Examiner-Abe Hershkovitz [57] ABSTRACT A pumping device having-a bellow-type pumping assembly having a stationary and an oscillating end portion, and a mechanism for reciprocating said end portion between a given minimum volume and an adjustable maximum volume position, the said mechanism including a spring biased connecting rod, designed to transmit a force not greater than a given value, and a motor reciprocated arm along which one end of said rod is pivotally connected at operator adjustable positions for modifying the actual length of said arm and therefore the amplitude of the variation of said volume, while the-pressure built-up in said chamber cannot be higher than that provided by the force which can be applied to said oscillating end portion by said spring biased rod.

5 Claims, 5 Drawing Figures PAIENTEDJUNZSW 1,808

SHKU 1 BF 2 PUMPING DEVICE FOR PROMOTING PATIENTS BREATHING BACKGROUND 1. Field of the Invention This invention is concerned with a pumping device, moreparticularly a motor driven and easily portable pumping device designed for cyclically and meteredly pumping oxygenated air-or other suitable gaseous mixture into a patients lungs, the device of the invention being particularly but not exclusi'vely suitable for emergency occurrences, accidents, and in general when spontaneous breathing may become seriously depressed and inadequate. I

2. Prior Art Several lungs ventilator devices for cyclically applying an overatmospheric pressure to a patients lungs are known. Such devices are designed for cyclically applying a pressure within'a chamber and on the outer surface of a collapsible bag or other variable volume reservoir connected in the circuit of an automatic lung ventilator apparatusfor providing the pulsing feed of the gaseous mixture to be cyclically and meteredly supplied into the patients lungs.

Such automatic ventilators are well known and made use of for improving surgery and anaesthesia standards for example, and in various occurrences when spontaneous breathing may become seriousli depressed and inadequate.

A very wide and exhaustive literature deals with the matter and therefore any further consideration thereabout is superfluous. It is however to be taken into consideration in view of the scope of this invention that the precise adjustment of the applied pressures, irrespective of the pulsing cycle, is critical and that other critical'features comprise the most desirable metering of the amount of gas to be supplied into the patients lungs, and that the mode by which the positive pressure is cyclically increased for-proper and effortless filling of the lungs alveolar spaces. Several devices have been heretofore proposed for alternatively applying positive pressure into a. variable pressure chamberwherein a breathing bag is located, devices generally comprising an alternating piston or bellows pump, wherein the piston or the movable end part of the bellows is reciprocated by a crank and connecting rod mechanism, the crank shaft making one complete 360 revolution at each respiratory cycle. Such pumps'have a stroke volume in excess of the gas volume to be supplied in the patients lungs at any respiratory cycle, and ports and limiting valves are provided for venting the variable pressure chamber to the atmosphere and for levelling the pressures at the desired values. A plurality of adjusting means are provided and are to be acted upon for maintaining the desired pressure and/orgas volume, when the frequency of the respiratory cycle is varied.

These known apparatuses are very large, heavy and costly too, and can be made use of only as stationary implements of surgery rooms and the like.

It is known to those skilled in the art that in a crank driven reciprocating pump the air input and output varies'according to a sinusoidal law, which provides a pretty progressive initial increasing of the flow. it has been found that an increase governed by such laws is not as progressive as desirable, while a proper filling of the lungs alveolar spaces would best be obtained by supplying in the variable pressure chamber amounts of air whose increase be defined by a initially flatter and finally steeper curve.

' It is therefore an object of this invention to provide a new and improvedpumping device including a variable volume chamber connected to suitable input and output passage means adapted to be conventionally connected, such as by means of a hose and a mask, with the patients mount and nose, and a mechanism connected to a movable component of such chamber for reciprocating such component from a minimum chamber volume position to an expanded chamber volume position, said mechanism comprising means adapted for varying the expansion of the chamber volume under operator's control and means for preventing that the pressure built-in said chamber would increase above a given value, while the amount of the gaseous mixture pumped ofi said chamber during the positive stroke of the pumping device remains unmodified.

Another object of this invention is to provide a new andimproved pumping device as above, including a structure and'a mechanism arranged within an assembly of generally small overall dimensions and weight and therefore adapted for transportation and use such as at the individual patient bedside, during a patient transportation, and even at the very location where and accident or crash has occurred, for ensuring survival of seriously wounded persons and so on.

THE INVENTION According to the invention, the device comprises a bellows-type variable volume chamber having a stationary head wall, a movable head wall and folding bellows side wall. The movable head wall has one end of a connecting rod pivotally connected thereto, the other end of such connecting rod being pivotally connected to a slide member which can be adjustably positioned along an arm oscillatably supported about an axis perpendicular to the plane wherein the said movable wall and connecting rod are movable, said arm being arcshaped and has its center essentially in the pivotal axis of the said one end connection of the said connecting rod when said chamber is at its minimum volume position,.whereby by adjusting the interval between the said slide member and the axisabout which the said arm oscillates for a" given angular amplitude, the cyclical variation of volume of said chamber can be adjusted without modifying the said minimum volume.

Further, the said connecting rod comprises spring means loaded to resist a given load only, so that the said rod can apply to the bellows a force not greater than said load and therefore a pressure higher than a given value cannot be built inside said chamber, irrespectively of the variation of the inner volume in such chamber.

Still further, the said oscillatable arm is reciprocated at a given angular amplitude about its axis by a motor and crank means including a crank and slotted link cranking device so selected (as to its geometrical parameters) to provide that the positive or pumping stroke of the bellows is completed during about of the revolution of the crank shaft, to provide the most proper adaptation of the pumping cycle to the human breathing cycle and to filling of the lungs alveolar spaces.

According to a still further feature of the invention, the slide member adjustably positionable along the arcshaped arm is screwly connected with a threaded rod supported for rotation on said arm about an axis intersecting the oscillation axis of the arm, and gearingly connected to a control shaft co-axial with said oscillation axis, whereby upon operator controlled rotation of said control axis the said threaded rod is rotated and the said slide member is spaced along the oscillating arm irrespectively of the position and actual motion, for providing operator controlled adjustment of the variation of the volume of the chamber, that is of the amount of the gaseous mixture pumped in each stroke.

These and other features and advantages of the invention will be made best apparent from the following detailed description of a preferred embodiment of the device, shown in the accompanying drawings.

THE VIEWS OF THE DRAWINGS FIG. 1 is a side elevational view and partly a crosssectional view, taken from plane indicated at II in FIG. 4, of the essential combination and arrangement of parts of the pumping device;

FIG. 2 is a graph which illustrates certain curves of the amplitude of motions of the driven parts of the mechanism as a function either of the rotational motion of the driving parts and of time, assuming as time unit that of a complete breathing cycle;

FIG. 3 is a view similar to that of FIG. 1, and illustrates the same device in a different phase and adjustment;

FIG. 4 illustrates the mechanism as seen generally from above and having parts in cross-section taken in planes containing several pivotal and oscillation axes; and

FIG. 5 illustrates in grater detail a valve means associated with the device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the device comprises a pumping assembly generally indicated at and including a variable volume chamber defined by a bellows-type side wall 12 having an end portion secured to a stationary plate 14 (forming part of the structure or frame of the device) and an opposite end portion secured to a movable plate 16 oscillatably supported at 18 to said frame structure. This construction has been preferred but not critical. It is however advantageous because it provides a variable chamber of simple construction, not including running seals and not requiring lubrication. It can be constructed with material adapted for ensuring the most complete asepsis and protection from contamination of the gaseous mixture to be pressurizedly fed into the patients lungs.

An annular flat end portion 20 of the bellows 12 is sealingly compressed between the oscillatable plate 16 and an inner plate 22. The bellows has a flange portion 24 integrally formed therewith, which is compressed between the stationary plate 14 and an annular member 26. Said stationary plate 14 has a pipe union 28 secured therethrough for the necessary hose connections (not shown) with the source of the gaseous mixture and with the patient's mask, and a shaped body 30 is secured within the variable volume chamber for occupying the major part of its volume when the said volume is at minimum (FIG. 1).

The pumping assembly is motor driven by a known motor, such as conventional variable speed motor (or connected to a variable speed transmission). The motor is fragmentarily shown at 74 in FIG. 4, and the source of power does not form part of the invention.

The pumping assembly, in particular the oscillatable plate 16 is connected to the drive mechanism by a pivotal connection 32 having a part secured to a flange 36 connected to said plate, by means of an adjusting screw. The pivotal connection at 32 forms one end of a connecting rod generally indicated at 38, the opposite end of which is formed by another pivotal connection 40 which can be adjustably positioned along an arcshaped groove 42 formed along a curved arm 44 oscillatably supported about an axis defined by a shaft 46, parallel to the pivotal axis at 18 about which the movable plate 16 can be oscillated. The said arc-shaped groove 42 has its center at the pivotal axis of connection 32, so that the position of minimum volume of the variable chamber (FIG. 1) will not be modified by displacing the connection at 40 along said groove 42.

On the other part, the amplitude of the stroke of the pumping assembly, that is of the oscillation of the movable plate 16, driven by the connecting rod or link 38, is evidently proportional to the amplitude of the reciprocation of the pivotal connection at 40, wherein the connecting rod 38 is driven. This latter amplitude, for a given oscillatory amplitude of the arm 44, is proportional to the spacing between the pivotal connection at 40 and the oscillatory axis at 46 of arm 44. Therefore, by displacing the said pivotal connection at 40 the volume of the gaseous mixture pumped by the assembly during each stroke can be widely and accurately adjusted, by adjusting the actual lenght L of the arm, upon constant amplitude of the oscillation AA of the arm, the thus adjustable amplitude C-C' of the 0scillatable plate 16 not modifying the contraction of the inner volume of the chamber, at the end of the positive stroke (in direction C) of the plate 16. It is evident that the above assumptions are valid upon assuming the length B of the connecting rod 38 constant.

According to an important feature of the invention, the connecting rod 38 consists of two coaxial components 52 and 54, telescopingly engaged and axially movable relatively to each other within the limits provided by the motion of a pin 56 secured to component 52 along a slot 58 grooved in component 54, a spring 60 being provided for biasing such components so that the connecting rod 38 is urged in its maximum length B, as illustrated in FIG. 1.

The same mechanism is illustrated in FIG. 3 while at midway about of the stroke C of the pumping assembly, and as set for pumping at smaller rate, upon adjustment of the pivotal connection at 40 along the groove 42, to provide an acting length L of the arm, smaller than the length L of FIG. 1. Further, FIG. 3 examplifles the occurrence that the pumping of the gaseous mixture has encountered a resistance greater than that of the force of the spring 60, so that the connecting rod has temporarily attained an actual length B smaller than that B of FIG. 1, the said connecting rod 38 tending to regain its original length as soon as such resistance will decrease or disappear.

According to another feature of the invention, the pumping assembly is driven so that its positive or pumping stroke will occur in about one/third of the entire time of one cycle, that is in about of a comillustrated in FIG. 4.The arm 44 is secured, by means of a tubular member 62 to anotherarm 64. Such member 62 is supported for rotation about the shaft 46, carried by'stationary supports 48 and 50. The arm 64 forms the driven component of the crank, more particularly it has a slot 66 whereina roller 68 can slide, said roller being carried by the crank pin 70 of a crank flywheel 72 driven by the motor means 74.

The radius of the crank pin path P iscorrelated (upon conventional techniques) to the spacing of the axis 0 ofthe crank wheel to the axis (at 46), so that the desired relationship of the forward stroke and backward stroke of the arms 44 and 64 is attained.

The adjustment of the position of the pivotal connection at 40 along the groove 42 can be made also while the mechanism is operated. Said pivotal connection is provided by a pin integral with a block 78 having a threaded bore engaged by a threaded rod- 76 rotatably supported by another block 92 having a part 94 rotatable about said shaft 46. The screw-threaded rod 76 is secured to a bevel gear 80 in mesh with another bevel gear 82 rotatable about the shaft 46 and connected, by means of another tubular member 84, to gears 86 and 88, the latter of which is secured tov a control shaft having an end 90 to which a handle wheel or another suitable means can be secured for rotating same. it is evident that such rotation can be actuated irrespectively of the motion of the reciprocating components, and will provide the displacement of the block 78 and thus of the pivotal connection at 40 for having the actual length L or L of the arm adjusted at will.

The pumping device is designed to be associated to a conventional breathing system (not shown) including hoses, a mesk and suitable sources of gaseous mixture, valves and so on. Such system comprises, as known to those skilled in the art, an one-way passage valve in the exhaust duct. It is advantageous that such valve would be positively open when the patient breathes-off to provide-minimal resistance. The device preferably comprises such valve also, generally indicated at 96, and a positive actuator for-opening thevalve in phase rela tionship to the pumping actuation.

This actuator comprises a rocking lever 98 pivotally supported at 120 and having a cam follower roller 100 atone end, said cam follower cooperating with a camming surface 102, 102' provided by the contour of the v crank fly-wheel 72.

This valve can be constructed as shown in FIG. 5. It comprises'an inlet union 104, an outlet union 106, a valve seat 108 on which a valve body 110 can sealingly seat, and a light spring 112 urging said body on said seat. Said body 110 is formed with a part 114 to which a stem 116 is secured and the said rocking lever abuts on one end of said stem for positively urging the valve body 110 in direction X, thus opening the valve, as the cam follower 100 runsalong the part 102 of greater radius of the camming surface. The structure of the valve preferably comprises two members 122 and 124 screwly secured to each other, to provide a simple and readily disassemblable device for inspection, cleaning and asepsis.

The graph of F IG. 2 illustrates some typical modes of operation of the device and its behaviour when a variable resistance is encountered in promoting the breathing of a patient.

The curve K illustrates the variation of the volume of the chamber (its maximum volume, apart from the adjustment, being indicated at l on the ordinate) as a function either of rotation R of the crankshaft and of the fraction of time T of an entire breathing cycle. The curveis regular and has its most desirable sharp increase after a very smooth beginning. The curve S illustrates, for comparison, a curve of the function of the sinus, as provided by a conventional cranking device. The maximum volume is attained at that is at onethird of the time of one cycle.

Assuming that during the positive (pumping) stroke C the outflow of the gaseous mixture would encounter a resistance to promptly fill the patients lungs, such to overcome the load of the spring 60, the curve K will flatten such as indicated at K for example, either slowing the filling of the lungs, such as in a time T longer than V: T, or eventually levelling same as indicated at K" for example, and in any case eliminating any hazard for overpressure applied to the patient.

it is evident that the invention provides a relatively simple, compact and reliable pumping device for the uses described, which can be readily adjusted for the most amplitude of variables to meet emergencies as well as for general treatment of patients, assistance to surgery and the like. The device is easy to be operated and does not lead to risks of overpressurizing and/or overfeeding oxygen or other mixture to the patient. Additionally, it has a positively controlled valve to be connected in the exhaust circuit, so that no hazard of defective or incomplete exhaustion of the patients lung is faced. a

I claim:

1. A motor driven pumping device for actuating a patients breathing assisting apparatus comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a given minimum to a maximum volume, and a springloaded valve; a mechanism including an oscillating arm anda connecting rod pivotally connected at opposite ends to said arm and to said reciprocating end portion; driven crank means for oscillating said arm at a given angular amplitude, said crank means comprising a flywheel rotatable about an axis, a crank pin eccentrically secured to said flywheel, a roller rotatably mounted on said pin, and means operatively connecting said roller to said oscillating arm for oscillating the latter during rotation of said flywheel, said flywheel having a camming surface extending about said axis; and cam follower meansengaging said camming surface of said flywheel and said spring-loaded valve for actuating the latter in phased relationship with said pumping device.

2. A device as defined in claim 1, wherein said flywheel has a peripheral surface having a first portion of greater radial distance from said axis of said flywheel than a second portion thereof, said peripheral surface constituting said camming surface engaged by said cam follower means.

3. A device as defined in claim 1, wherein said connecting rod is pivotally connected at one end to said reciprocating end portion and including a component adjustably connected to said oscillating arm and pivotally connected to the other end of said connecting rod to provide an operator controlled adjustment for the acting length of said oscillating arm from the axis of pivotal connection of said other end to the axis about which said oscillating arm oscillates, said component being displaceable lengthwise of said arm along an are having its center substantially at the axis at which said connecting rod is pivotally connected to said reciprocating end portion when said assembly is in a position at which said chamber has a minimum value.

4. A motor driven pumping device for actuating a patients breathing assisting apparatus comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a given minimum to a variable maximum volume; a mechanism including a stationary shaft, an oscillating arm pivotally mounted in the region of one end on said shaft and provided with an arc-shaped groove extending lengthwise of said oscillating arm, a block slidably displaceable along said groove and having a bore provided with an inner screw thread, a rod provided with an outer screw thread threadingly engaged with said inner screw thread of said bore, a connecting rod pivotally connected at opposite ends to said reciprocating portion and said block, driven crank means for oscillating said arm about the axis of said shaft and including a slotted arm, a first tubular member rotatably supported about said shaft and fixedly secured to said oscillating arm and said slotted arm of said crank means,

threaded rod perpendicularly to the axis of said shaft, a first bevel gear fixedly secured to said rod adjacent to said second tubular member, a third tubular member rotatably supported about said shaft and having a second bevel gear fixedly secured thereto in mesh with said first bevel gear, and actuator means connected to said third tubular member for rotating the same.

5. A motor driven pumping device comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a minimum to a maximum volume; rotatable crank means; and motion transmitting means between said crank means and said reciprocating end portion of said bellows for moving said reciprocating end portion along a pumping stroke reducing the volume of said chamber and an opposite stroke, said motion transmitting means comprising an oscillating arm oscillated by said crank means, a connecting rod including two telescopically fitted components pivotally connected to said reciprocating end portion and to said reciprocating arm, respectively, and spring means for delaying the motion transmitted to said reciprocating end portion when the pressure built up in said chamber during said pumping stroke reaches a given value, said spring means being interposed between said components and loaded to transmit a force to said reciprocating end a second tubular member rotatably supported about portion not greater than that necessary to build up a said shaft and having a second block fixedly secured thereto, said second block rotatably supporting said pressure of said given value in said chamber. 

1. A motor driven pumping device for actuating a patient''s breathing assisting apparatus comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a given minimum to a maximum volume, and a spring-loaded valve; a mechanism including an oscillating arm and a connecting rod pivotally connected at opposite ends to said arm and to said reciprocating end portion; driven crank means for oscillating said arm at a given angular amplitude, said crank means comprising a flywheel rotatable about an axis, a crank pin eccentrically secured to said flywheel, a roller rotatably mounted on said pin, and means operatively connecting said roller to said oscillating arm for oscillating the latter during rotation of said flywheel, said flywheel having a camming surface extending about said axis; and cam follower means engaging said camming surface of said flywheel and said spring-loaded valve for actuating the latter in phased relationship with said pumping device.
 2. A device as defined in claim 1, wherein said flywheel has a peripheral surface having a first portion of greater radial distance from said axis of said flywheel than a second portion thereof, said peripheral surface constituting said camming surface engaged by said cam follower means.
 3. A device as defined in claim 1, wherein said connecting rod is pivotally connected at one end to said reciprocating end portion and including a component adjustably connected to said oscillating arm and pivotally connected to the other end of said connecting rod to provide an operator controlled adjustment for the acting length of said oscillating arm from the axis of pivotal connection of said other end to the axis about which said oscillating arm oscillates, said component being displaceable lengthwise of said arm along an arc having its center substantially at the axis at which said connecting rod is pivotally connected to said reciprocating end portion when said assembly is in a position at which said chamber has a minimum value.
 4. A motor driven pumping device for actuating a patient''s breathing assisting apparatus comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a given minimum to a variable maximum volume; a mechanism including a stationary shaft, an oscillating arm pivotally mounted in the region of one end on said shaft and provided with an arc-shaped groove extending lengthwise of said oscillating arm, a block slidably displaceable along said groove and having a bore provided with an inner screw thread, a rod provided with an outer screw thread threadingly engaged with said inner screw thread of said bore, a connecting rod pivotally connected at opposite ends to said reciprocating portion and said block, driven crank means for oscillating said arm about the axis of said shaft and including a slotted arm, a first tubular member rotatably supported about said shaft and fixedly secured to said oscillating arm and said slotted arm of said crank means, a second tubular member rotatably supported about said shaft and having a second block fixedly secured thereto, said second block rotatably supporting said threaded rod perpendicularly to the axis of said shaft, a first bevel gear fixedly secured to said rod adjacent to said second tubular member, a third tubular member rotatably supported about said shaft and having a second bevel gear fixedly secured thereto in mesh with said first bevel gear, and actuator means connected to said third tubular member fOr rotating the same.
 5. A motor driven pumping device comprising, in combination, a bellows-type pumping assembly having a stationary end portion and a reciprocating opposite end portion for cyclically varying the volume of a chamber defined between said end portions from a minimum to a maximum volume; rotatable crank means; and motion transmitting means between said crank means and said reciprocating end portion of said bellows for moving said reciprocating end portion along a pumping stroke reducing the volume of said chamber and an opposite stroke, said motion transmitting means comprising an oscillating arm oscillated by said crank means, a connecting rod including two telescopically fitted components pivotally connected to said reciprocating end portion and to said reciprocating arm, respectively, and spring means for delaying the motion transmitted to said reciprocating end portion when the pressure built up in said chamber during said pumping stroke reaches a given value, said spring means being interposed between said components and loaded to transmit a force to said reciprocating end portion not greater than that necessary to build up a pressure of said given value in said chamber. 